Stats Final Exam

Question 1

what is an example of a continuous variable

Answer 1

age, weight, height

Question 2

what does correlation describe

Answer 2

how variables will co-vary; whether they behave similarly or differently

Question 3

what symbol expressions correlation

Answer 3

pearsons r

Question 4

what r value indicates no relationship between X and Y

Answer 4

0

Question 5

what is X

Answer 5

the predictor

Question 6

what is Y

Answer 6

the outcome

Question 7

what r values are perfectly correlated

Answer 7

1 or -1

Question 8

what is the expected correlation between variables

Answer 8

0

Question 9

r <= .10 is

Answer 9

trivial

Question 10

r < .30 is

Answer 10

small

Question 11

r< .50 is

Answer 11

medium

Question 12

r >= .50 is

Answer 12

large

Question 13

what is a linear relationship

Answer 13

the best way to summarize the trend in the data is with a straight line

Question 14

what is a quadratic relationship

Answer 14

the best way to summarize data is with a curved line

Question 15

what are the 3 elements of causality

Answer 15

1. correlation
2. temporal precedence
3. ruling out alternative explanations

Question 16

the only reliable method to determine causality is with…

Answer 16

experimentation

Question 17

most correlations are not implying…

Answer 17

causality

Question 18

what does OLS stand for

Answer 18

ordinary least-squared regression

Question 19

what is OLS

Answer 19

the smallest distance between Y and Y(hat)

Question 20

what is Y(hat)

Answer 20

predicted value of the constant when x has certain qualities

Question 21

what does it mean for Y(hat) when a predictor is non-significant

Answer 21

that Y(hat) doesnt change as the X value changes

Question 22

what does it mean for Y(hat) when a predictor is significant

Answer 22

that Y(hat) changes as X value changes

Question 23

what do you do when you’re asked to estimate an out-of-range value

Answer 23

decline! point out the model (OLS) does not allow this

Question 24

what is NOIR with examples

Answer 24

Nominal (gender)
Ordinal (military rank)
Interval (temperature C)
Ratio (weight, age, height)

Question 25

continuous data relies on what

Answer 25

the mean

Question 26

what does parametric mean

Answer 26

they have many underlying assumptions

Question 27

what does non-parametric mean

Answer 27

they have fewer underlying assumptions

Question 28

is chi-squared parametric or non-parametric

Answer 28

non-parametric

Question 29

if data is continuous, what will likely make an appearance

Answer 29

t-tests

Question 30

what is the basic idea of t-tests

Answer 30

difference/error

Question 31

chi-squared tests are a calculation of

Answer 31

what we expected the answer to be, and what the answer was

Question 32

what is needed for an average

Answer 32

mean and standard deviation

Question 33

what does categorical data not have

Answer 33

the necessary elements of an average (mean and SD)

Question 34

categorical data can not be...

Answer 34

averaged!

Question 35

what are 2 reasons you may use categorical data

Answer 35

1. high variance implies different issues, and converting to categories solves this problem 2. sometimes group size is too small to facilitate a normal analysis, so we collapse data

Question 36

you cannot go from categorical data to...

Answer 36

continuous data

Question 37

what are the two flavours of chi-square tests

Answer 37

1. goodness of fit 2. tests of independence

Question 38

what is goodness of fit

Answer 38

is if data from 1 variable meets expected proportions

Question 39

what is tests of independence

Answer 39

describe if there is a non-random association between 2 variables

Question 40

what are 2 basic assumptions of chi-square

Answer 40

1. independence of observations 2. size of expected frequencies

Question 41

what is independence of observations (chi-sqaure)

Answer 41

persons can only give data for one cell (ex. name) theres only one answer

Question 42

what are some examples of GOF tests

Answer 42

1. are men/women equally likely to be lawyers 2. are Canadian university professors more likely to be a non-minority 3. are left-handed people more likely to be divorced

Question 43

what must be known for GOF

Answer 43

only makes sense is proportions are known; need a baseline

Question 44

what are all GOF tests based on

Answer 44

general population

Question 45

what is fe

Answer 45

frequency of expected

Question 46

tests for independence uses....

Answer 46

frequency data to evaluate the relationship between two variables

Question 47

what does effect size describe

Answer 47

the magnitude of difference between groups; extent to which the null hypothesis is incorrect

Question 48

what is cramer's V

Answer 48

a statistic to calculate the effect size of chi-square

Question 49

what type of effect size to be want

Answer 49

large

Question 50

what changes the standards for small, medium, and large effect sizes

Answer 50

degrees of freedom